As I recall, that is an average extrapolated from the data Rossi gave in the Lewan interview. See:
mail-archive.com/vortex-l%40eskimo.com/msg109919.html
I'm confused. And I'm asking these questions with sincerity.
The link you provided is to conjecture by Daniel Rocha. While interesting, it does not appear to contain any hard measured temperature values. Do you have a different link to the data provided by Rossi?
I do not have the data I received on this computer, but I recall the
temperatures were low. There were other indications the fluid was water,
not steam.
Where did this data come from, and what happened to it after you received it (i.e., why don't you have it any more)? Is this data that IH had shared with you? When you say you recall the temperatures were low, were these measured temperatures? Can you provide a ballpark range for what you remember?